<template>
  <!-- 遮罩层 -->
  <div class="mask "></div>
</template>
<script>
</script>
<style>
.mask {
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  position: fixed;
  left: 0;
  top: 0;
  z-index: 3;
}
</style>